Heat-insulating-material mat, in particular for building construction, and method for producing the same

ABSTRACT

The present invention relates to a heat-insulating-material mat ( 10 ) in particular for building construction, which is formed from layers ( 1, 2, 3, 4,  etc.) which are arranged loosely one above the other and are made of insulating materials which fuse together exclusively under the heat of a standard flame of a fire test conducted in accordance with standard DIN EN ISO 11925-2 and are held together by means of at least one seam ( 31, 32, 33 ) which is configured in undulating form in the longitudinal direction (X) and/or transverse direction (Y) of the mat ( 10 ) and in the case of which at least one thread ( 20, 21, 22 ) is guided through the layers ( 1, 2, 3, 4,  etc.), wherein the undulating form of the seam ( 31, 32, 33 ) is dimensioned such that, constantly changing in position in relation to the local surface area of the standard flame, it moves out of the local flame-treatment surface area. A method for producing heat-insulating-material mats ( 10 ) making use of a multi-needle sewing machine is also claimed. The heat-insulating-material mat ( 10 ) according to the invention, which can be supplied in a variant which is closed to diffusion and in a variant which is open to diffusion, is suitable for insulating static objects such as roofs, walls/facades or floors and also for lining, for example, drivers&#39; cabs, caravans and other means of transport.

The present invention relates to a heat-insulating-material mat, inparticular for building construction, which is formed from layers whichare arranged one above the other, which are held together by means of atleast one seam which is configured in undulating form in thelongitudinal direction (Y) and/or transverse direction (X) of the matand in the case of which at least one thread is guided through thelayers, as well as the method of producing same heat-insulating-materialmats.

There are diverse heat-insulating-material mats known, which are formedparticularly from composite layers which are arranged and combined oneabove the other made out of different materials.

For example the DE 101 01 966 B4 manifests a heat-insulating-materialmat and/or sound proofing material for the building construction, whichis formed of composite materials with layers arranged one above theother, whereas one composite material is minimum one layer of metalizedlayer, minimum one Polyolefin-layer and minimum a layer of air cushion,whereas one Polyolefin layer is made of a high density Polyethylene foiland minimum one Polyolefin layer is made of foamed Polyethylene foil,after it was discovered, that foamed Polyethylene foil in combinationwith metalized foil, high density Polyethylene foil and/or air cushionshave proven to have very good insulating properties.

In order to handle all layers it is known, that these, especially in thecorner margins, have to be hold together/connected by means of seamsand/or welds and/or staples.

The DE 100 01 7781 A1 reveals a compound system, including one ormultiple sheets of poly foam panels which are open celled, flexible andinclude good sound-proofing properties, which are made of a mix ofmelamine and formaldehyde resin and one or more layers of fiber fleeceor fiber fabric, whereas the sheets and layers are connectedmechanically through stitching, quilting, stapling, nailing andriveting.

It is known from the DE 42 42 261 A1 that this is a procedure of coatingplastic foam sheets with mortar or similar, especially for structuralwall panels used as tile backer board, whereas in order to improve themechanical integrity a fabric is intended in the mortar layer, which issewn onto the plastic foam sheet or the fabric texture is evolvingthrough the stitching together of the plastic foam sheet.

The DE 600 26 541 T2 reveals a procedure for production of a coating foran insulation material, whereas a layer of synthetic material, whichincludes a polyamide, is extruded onto a surface of a metal layer insuch a way that the synthetic material and the metal layer are fusedtogether, and whereas after the fusion of the metal layer and thesynthetic material layer the coating is heated in a certain way between100 and 160° C., in order to crystallize the polyamide.

It is known from the DE 1 778 733 U that there is a sheet for floor- orwall covering, in which strips of felt are connected throughzig-zag-seams, whereas zig-zag-seams are described as patterns of shortdistances, which are arranged in always the same angles towards eachother, and whereas the felts which are connected through thesezig-zag-seams are fastened differently onto a slip resistant substructure, f.e. made out of foamed material.

In the course of the approval certification have mats of a similarcategory according to the standard DIN EN ISO 11925-2:20111-02 (“testsfor fire behavior—inflammability of products under direct flameimpact—part 2: single flame test”) to pass various fire tests in whichthe mats and their connecting material (seams) are exposed to definedlocalized flames (norm flames).

In order to adhere to the current fire protection regulations, it isknown, that at least one layer or all layers have to be flame retarding,whereas the for this purpose appropriate method for the coatingrespective inclusion of flame retardant chemicals onto the respectivefoils is being known and therefore is not to be mentioned here indetail.

For the protection against tearing of the metalized outer layers ofsimilar categorized mats during the installation f.e. in the attic of abuilding the DE 101 01 966 B4 resorts to the use of relatively thickouter layers with a thickness of 0.03 mm and 0.2 mm, because knownalternatives such as very thin metalized outer foils with a thickness off.e. 0.012 mm and reinforced by glued textile grits are constantly runcontrary to the fire certification, because glue usually works as a fireaccelerant.

The problem with this is that mats with metalized outer foils with athickness of more than 0.03 mm usually do not melt under the heat of alocalized (norm) flame, but they continuously transfer the heat into themat, which starts to burn after reaching the lowest level of flash pointof one of the used materials.

Based thereof the underlying purpose of the invention at hand is,compared to the current state-of-heat-insulation-mat-technology, tosupply an improved heat-insulating-material mat, which in particularavoids the aforementioned drawbacks and at the same time fulfills therequired fire protection regulations.

This task is resolved through a heat-insulating-material mat, inparticular for building construction, based upon the attributes of theindependent patent requirement 1 and also through the method ofproducing heat-insulating-material mats according to the attributes ofthe patent requirement 14.

The subject of the attached claims is the beneficial developments anddevelopment advancements which are to be used individually or inconjunction.

Compared to heat-insulating-material mats in the similar category theinvented heat-insulating-material mat is different such as that alllayers are loosely arranged above each other, which are solely made outof materials which melt (fuse) together onto themselves under the normflame, whereas said norm flame conforms to the testing procedure of DINEN ISO 11925-2:2011-02.

It was discovered that if you resort to solely materials which melt(fuse) together onto themselves, the norm flame is just burning a holein the mat, which results in an advantageous prevention of acontinuously induction of heat into the mat and thus the ignition of themat at the lowest flash point is avoided.

Although, with such a test configuration it showed that if you usestraight lines of thread on the edges and in the middle, of which onethread is going straight through all layers, this thread stimulates theignition of the heat-insulating-material mat like a wick, and thereforethe striven certification “normal inflammable” (“B2” after DIN 4102-1respective “E” after the European classification DIN EN 13501-1) wasdenied.

Compared to similar category heat-insulating-material mats theaccomplished invented heat-insulating-material mats have at least oneseam in undulating form in the longitudinal direction (Y) and/ortransverse direction (X) wherein the undulating form of the seam isdimensioned such that, constantly changing in position in relation tothe local surface area of the norm flame, it moves out of the localflame-treatment surface area.

The undulating form of the seam has therefore the advantage, that thisundulating seam does not—contrary to straight seams—stay within thelocal area of the norm flame or springs back therein—as zig-zag-seams—,but is dimensioned such that, constantly changing position in relationto the local surface of the area of the norm flame, it moves out of thelocal flame-treatment surface, this in consequence avoids a wick effectof the seam thread and ignition of the used materials, which fusetogether within the scope of the test norm.

Depending on the width of the mat, which is assembled assimilated uponthe usage and/or building construction possibilities and f.e. isapproximately 120 cm for consumers (private) or approximately 150 cm forcommercial users, mats have proved themselves, which have in particularat least two, preferably three or maximum five undulating seams goingthrough the layers, whereas neighbouring of the transverse edge of themat, preferably with a distance of approximately 20 mm to the transverseedge, an undulating outer seam and/or right in the center of thetransverse edge of the mat an undulating center seam and/or between thetransverse edges of the mat and the center of the mat each an undulatinginner seam has to be guided through the layers.

An undesirable wick effect is avoided, if the distance between twoundulating seams is a minimum of 90 mm. Through compliance of a minimumdistance there is the advantageous formation of air layers in betweenthe single layers which are held together by the seams. Through theformation of air layers between the single layers it is possible that aninflation between the undulating seams is accomplished, so that inpractice a significant raise in the heat transfer resistance is to beseen, which is usually only theoretically to be calculated.

An undesirable wick effect is also been avoided, if the repeat length(y) is f.e. approximately 150 mm, which is defined by the distance oftwo consecutive maximum or minimal undulations, the undulation amplitude(x) which is also called peak-to-valley ratio, and is defined throughthe distance between maximum and minimum, should be minimumapproximately 40 mm, preferably approximately 50 mm.

For the formation of air layers between the single layers it issupportive, if based on a f.e. undulating seam of approximately 180 mm(the real length of the undulating seam) preferably not more thanapproximately 36 needle stitches are guided through the layers, so thatthis results in a preferred stitch length of 5 mm for each undulatingseam, so that the loosely arranged layers on top of each other areadequately permeable to air and at the same time are held together.

From the invention side it is preferred to have minimum one,particularly two, preferably four, rows of perforation holes guidedthough the layers, where the course of each row of the perforation holespreferably have the same undulating form as the corresponding undulatingseam. The perforation holes guarantee a diffusion openness of the matand the advantageous usage in an outside section before the vapourbarrier with an otherwise identical configuration.

Alternatively or accumulatively it has been proven to use threads withcapillary effects in order to avoid a moisture build up.

Claimable is also a method of producing heat-insulating-material mats,especially present invention related mats, with the use of amulti-needle sewing machine.

From the invention side it is preferred to stitch the seams and/or rowsof perforation holes via needles from a multi-needle sewing machine,preferably during the same work process, which permits the inexpensiveproduction of the invented mats. Thereby with the diffusion open versionof the mat it is possible to implement additional needles without threadin the sewing machine, which can punch the holes during the same workcycle as the stitching is done.

The high thermal insulation effect of the present inventedheat-insulating-material mats is achieved thus heat and cold reflects onmetalized, f.e. vapour coated with aluminum and/or bronze and ergosilver—and or gold colored mirroring occurs, outer layers made out ofpolyester foil, which is made preferably flame retardant, f.e. through acoating of LDPE (“low density polyethylene”). Alternatively a coated,fabric reinforced aluminum composite foil can be used as outer layer aswell.

In order to have the metalized outer layers or aluminum composite foilsof the mat fused together under the heat of the norm flame they have apreferred thickness of f.e. only 0.012 mm. To protect from rippingthrough the material when installed it is preferably intended byinvention a strengthening of the polyester foil through a textileprinting process.

Advantageously this eliminates the use of fire accelerant glues andensures at the same time a sufficient stability of the outer layers ofthe mat during installations.

Depending on requirement and place of application it is possible to havemultiple inner layers between the outer layers, whereas it is preferred,if at least one inner layer of the mat is made out of flame retardantpolyester fleece; and/or a soft foam made out polyethylene; and/or oneinner layer is made out of a double-sided aluminum and/or bronze vapourcoated polyester foil, whereas the latter has to be stored over 48 hoursat 70° C. and 50% humidity and then preferably and irreversibly isundulating in the direction of the thickness (z) of the mat andbeneficially supports the forming of air layers between the singlelayers and ergo supports the inflation between the undulating seams.

In order to install/use the mat left- or right sided a layer formationof the mat has proven to be best in which the layers are arrangedsymmetrically from the outside to the inside.

Because the crucial characteristic of the high thermal insulation effectof the present invented heat-insulating-material mat is its reflectioneffect and not the thickness of the material, it has proven best to bemade out of fourteen layers, which has the following assembly of layersseen from the outside to the inside: one first layer, one second layer,one third layer, two fourth layers, one third layer, two fourth layers,one third layer, two fourth layers, one third layer, one second layerand one first layer.

In order for the present invented heat-insulating-material mat to beused easily by both consumers (private) and commercial applicants it hasproved to be the best to compile the materials and thicknesses of thelayers as follows: the heat-insulating-material mat has a deliveredthickness of a minimum of 7 mm, preferably an average of 11 mm andmaximum 20 mm, and also a total area weight of a minimum of 436g/m²+/−10%.

The heat-insulating-material mat according to the invention is suitablefor insulating static objects such as roofs, walls/facades or floors andalso for lining f.e. drivers' cabs, caravans (RV's) and other means oftransport.

Additional details and more advantages of the present invention aredescribed in the following application example and the supplied drawingof the multilayer heat-insulating-material mat, which does not mean thatthe present invention is limited to the described installation.

It is shown schematically:

FIG. 1 shows a multilayer heat-insulating-material mat drawn after thepresent invention, unrolled in a perspective view;

FIG. 2 shows the preferably fourteen layer comprehensive composition ofthe heat-insulating-material mat as per FIG. 1; and

FIG. 3 shows a part of the heat-insulating-material mat as per FIG. 1after a conducted fire test

In the following description of one preferable composition of thepresent invention the same reference signs are standing for the same orcomparable components.

FIG. 1 shows a multilayer heat-insulating-material mat 10 after thepresent invention. The shown heat-insulating-material mat consist f.e.of fourteen loosely arranged layers one above the other 1,2,3,4 . . . ,in particular made out of foils, fleeces and soft foams. Theheat-insulating-material mat 10 can be assembled from the outside to theinside as seen in the following table:

Outside

Thickness Weight/area Layer no Material Layer sequence (mm) (g/m²) 1 1Aluminum vapour coated polyester foil, LDPE aprox. 0.012 aprox. 60coated, flame retardant, fabric reinforced or coated, fabric reinforcedaluminum composite foil 2 2 Flame retardant polyester fleece aprox. 0.7aprox. 70 3 3 Double sided metalized—preferably aluminum or aprox. 0.012aprox. 20 bronze vapour coated-polyester foil 4 4 Polyethylene soft foamaprox. 1 aprox. 27 5 4 Polyethylene soft foam aprox. 1 aprox. 27 6 3Double sided metalized—preferably aluminum or aprox. 0.012 aprox. 20bronze vapour coated-polyester foil 7 4 Polyethylene soft foam aprox. 1aprox. 27 8 4 Polyethylene soft foam aprox. 1 aprox. 27 9 3 Double sidedmetalized—preferably aluminum or aprox. 0.012 aprox. 20 bronze vapourcoated-polyester foil 10 4 Polyethylene soft foam aprox. 1 aprox. 27 114 Polyethylene soft foam aprox. 1 aprox. 27 12 3 Double sidedmetalized—preferably aluminum or aprox. 0.012 aprox. 20 bronze vapourcoated-polyester foil 13 2 Flame retardant polyester fleece aprox. 0.7aprox. 70 14 1 Aluminum vapour coated polyester foil, LDPE aprox. 0.012aprox. 60 coated, f lame retardant, fabric reinforced or coated, fabricreinforced aluminum composite foil

Inside

In order to affix the layers 1,2,3,4 . . . together these layers areattached on both transverse corners respective transverse edges 11 ofthe mat 10 to each other with an undulating outer seam 31 and also withan undulating middle seam 32 in the middle of the mat 12, especiallysown together with the help of a multi-needle sewing machine (notshown). As shown it is possible to include an inner seam 33 between theouter seam 32 and the middle seam 32.

FIG. 2 shows according to above listed table the preferably comprisingfourteen layers 1,2,3,4 symmetrical composition of the layers of themat. It is comprehendible, that through the irreversible undulation ofthe inner, double sided aluminum and/or bronze vapour coatedpolyethylene foils 3, they are able to lift especially the polyethylenesoft foam 4 and enable an air layer build up between the layers 2,3,4 inorder to enhance the thermal insulation value R.

FIG. 3 shows a part of the mat 10 as per FIG. 1 after a fire test.

Firstly it is visible, how the undulating form, looking like a sinusoidcurve, of each of the seams 31, 32 or 33 do not stay in the local areaof the norm flame—which in FIG. 3 burnt a hole 60 in the mat—but changedthereof their position constantly, especially tangential, through theundulating pattern of the seams which are moving out of the local flametreatment, and because of this, a wick effect of the seam threads 20, 21and/or 22 and ignition of the used materials is avoided. The undulatingform of the seam which is changing constantly position is advantageousfire prevention wise with a repeat length (y) of f.e. approximately 150mm and is warranted particularly with regards to an undulating amplitude(x) of a minimum of approximately 40 mm, preferably approximately 50 mm,or the repeat length (y) and undulating amplitude (x) ratio of each ofthe undulating seams is approximately 1:3.75 or preferably 1:3.0.

The present invented heat-insulating-material mat 10 is suitable inparticular for the insulation of roofs, walls/facades or floors, whichis described as follows:

A thermal loss, which is caused by wind or wide area air movements(called convection), can be achieved through a separation of an interiorroom from the exterior room (air and wind tightness). The same appliesfor water permeation. This separation is achieved by installing thepresent invented heat-insulating-material mat 10 at its interfaces,usually at the transverse edges 11, with a minimum overlap of 50 mm. Inan application of a steep roof with a low roof pitch less than 20° theoverlap should be 80 mm. The minimum installation temperature should beat least 10° C., with a maximum humidity of 65%. Ergo the presentinvented heat-insulating-material mat 10 can either be used as roofunderlay in order to achieve wind proofing or as means to achieve airimpermeability as air tightness foil.

The—preferably laid out in rows—heat-insulating-material mats 10 aresealed together afterwards with the use of an adhesive aluminum orbronze tape centered on top of the interface/overlap (top and bottom andsides). In this process the outside edges 31 are sealed as well. As soonas the center seam 32 and any possible inner seams 33 are sealed withthe adhesive tape, you will achieve a diffusion closed surface, which iscomparable advantageously to a vapour barrier, which f.e. is intendedbeneath the roof trusses, in order to prevent the penetration ofmoisture from the interior (f.e. any wet cells) into the roof structure.

In an alternative diffusion open variant of the present inventedheat-insulating-material mats 10 it is intended to have rows ofperforation holes 40 besides the undulating seams, which allow theapplication of the otherwise similar heat-insulating-material mats 10 asvapour permeable mats above the roof trusses. In this application thecenter seam 32 and any possible inner seams 33 do not have to be sealedwith tape.

Based upon the low grade of emissions and the related high grade ofreflection of the surface of the heat-insulating-material mat in theinfrared sector the heat transfer mechanism is almost fully eliminatedwithin the bordering air layers. In practice the heat transfer takesplace only through heat conduction and convection. Therefore the anywayconstruction wise necessary air layers and installation levels can beused as thermo-technically relevant layers. If the present inventedheat-insulating-material mat 10 is visible from the inside or outside oris used in ventilated air spaces, then the internal or external heattransfer resistance is raised, therefore the thermal insulationperformance is enhanced additionally.

Based upon the considerably larger dependency of convection towardsnon-reflective insulating materials the results for the thermalinsulation ratings are varied depending on the direction of thermalenergy flow. Therefore the heat protection of a flat roof in summer isconsiderably higher than in winter.

The—preferably laid out in rows—heat-insulating-material mats 10 shouldbe fastened onto the fastening surface (mostly battens) approximatelyevery 80 mm with at least 20 mm deep/long staples or roof nails.

A nail strip has to be used at the nail holes respective staple holes.All surfaces, which are forming a heat loss zone, should be covered inpresent invented heat-insulating-material mat 10.

The heat-insulating-material mat 10 according to the invention, whichcan also be seen as almost diffusion closed in combination with thetaped seams, is rendered diffusion open through micro perforation.Depending on the numbers and size of the micro pores which thus createthe thermal diffusion behavior, it is then possible that the mat 10 isused diffusion open.

The heat-insulating-material mats 10 according to the invention istherefore suitable for insulating roofs, walls/facades, floors andceilings and also can be used in f.e., drivers' cab, caravans (RV's),container, cold storages (refrigerated ware houses), technicalfacilities etc. and the mat can use the surrounding air layers asadditional thermal insulation.

Based upon the multi layer composition and the chosen materials there isa good shielding effect against high frequency waves. It is alsopossible to have a shielding against low frequency waves through agrounding of the mats 10.

LIST OF REFERENCE SIGNS

-   1 first layer, outer layers, in particular: coated, fabric    reinforced aluminum composite polyester foil-   2 second layer, inner layer, in particular: flame retardant    polyester fleece-   3 third layer, inner layer, in particular: double sided aluminum    and/or bronze vapour coated polyester foil-   4 fourth layer, inner layer, in particular: polyethylene soft foam-   10 heat-insulating-material mat-   11 transverse edges of the heat-insulating-material mat 10-   12 center of the mat-   20 thread-   21 top thread-   22 bottom thread-   31 outer seam-   32 center seam-   33 inner seam-   40 rows of perforation holes-   50 pressure applied fabric reinforcement-   60 burn hole inflicted by norm flame-   X transverse direction of heat-insulating-material mat 10-   Y longitudinal direction of heat-insulating-material mat 10-   Z thickness direction of heat-insulating-material mat 10-   y repeat length of the seams 31, 32, 33 respectively the row of    perforation holes 40-   x undulating amplitude of the seams 31,32,33 respectively of the    rows of perforation holes 40

1. a heat-insulating-material mat (10) in particular for buildingconstruction, which is formed from layers (1,2,3,4 . . . etc.) which arearranged loosely one above the other and are made of insulatingmaterials which fuse together exclusively under the heat of a norm flameof a fire test conducted in accordance with standard DIN EN ISO 11925-2and are held together by means of at least one seam (31,32,33) which isconfigured in undulating form in the longitudinal direction (X) and/ortransverse direction (Y) of the mat (10) and in the case of which atleast one thread (20,21,22) is guided through the layers (1,2,3,4, . . .etc), wherein the undulating form of seam (31,32,33) is dimensioned suchthat, constantly changing in position in relation to the local surfacearea of the norm flame, it moves out of the local flame-treatmentsurface area.
 2. heat-insulating-material mat (10) of claim 1, that aminimum of two (31,31), preferably three (31,32,31) and maximum five(31,33,32,23,31) undulating seams are guided through the layers (1,2,3,4. . . etc), whereas particularly neighbouring to the transverse edge(11) of the mat (10), preferably with a distance of approximately 20 mmto the transverse edge (11), an undulating outer seam (31) and/orcentered between the transverse edges (11) of the mat (10) an undulatingcenter seam (32) and/or between the transverse edges (11) of the mat(10) and the center of the mat (12) each an undulating inner seam (33)are guided through the layers (1,2,3,4 . . . etc.). 3.heat-insulating-material mat (10) of claim 2, that the distance betweenthe undulating seams (31,32,33) is a minimum of 90 mm 4.heat-insulating-material mat (10) of claim 1, that the repeat length (y)of f.e. approximately 150 mm of the undulating amplitude (x) of each ofthe undulating seams (31,32,33) is a minimum of approximately 40 mm,preferably approximately 50 mm.
 5. heat-insulating-material mat (10) ofclaim 1, that with an undulating seam of approximately 180 mm preferablynot more than approximately 36 needle stitches are guided through thelayers (1,2,3,4, . . . etc), so that this results in a preferred stitchlength of 5 mm for each undulating seam (31,32,33) 6.heat-insulating-material mat (10) of claim 1, that between two seams(31,32,33) a minimum of one, particularly two, preferably four, rows ofperforation holes (40) are guided through the layers (1,2,3,4, . . .etc) whereas the course of each row of perforation holes (40) has to bepreferably of the same undulating form corresponding to the seams(31,32,33).
 7. heat-insulating-material mat (10) of claim 1, that thethreads (20,21,22), with which the layers (1,2,3,4, . . . etc) are heldtogether, exhibit capillary effects.
 8. heat-insulating-material mat(10) of claim 1, that the seams (31,32,33) and/or the rows ofperforation holes (40) are executed with needles of a multi-needlesewing machine, preferably during the same work process 9.heat-insulating-material mat (10) of claim 1, that the outer layer (1)of the mat (10) is a coated, fabric reinforced aluminum compositepolyester foil (1)
 10. heat-insulating-material mat (10) of claim 1,that at least one inner layer (2,3,4 . . . etc) of the mat (10) is aflame retardant polyester fleece (2); and/or is a double sided aluminumor bronze vapour coated polyester foil (3), which has to be stored over48 hours at 70° C. and 50% humidity and then preferably and irreversiblyis undulating in the direction of the thickness (z) of the mat (10);and/or is a soft foam (4) made out of polyethylene 11.heat-insulating-material mat (10) of claim 1, that the layers(1,2,3,4,4,3,4,4,3,4,4,3,2,1) of the mat (10) are assembledsymmetrically from the outside to the inside. 12.heat-insulating-material mat (10) of claim 1, that the mat (10)encompassed fourteen layers (1,2,3,4, . . . etc), which are assembledfrom the outside to the inside as follows: one first layer (1), onesecond layer (2), one third layer (3), two fourth layers (4), one thirdlayer (3), two fourth layers (4), one third layer (3), two fourth layers(4), one third layer (3), one second layer (2) and one first layer (1).13. heat-insulating-material mat (10) of claim 1, that materials andthickness of the layers (1,2,3,4, . . . etc) are put together such as,that the mat (10) has a minimum thickness at least 7 mm, preferably ofan average of 11 mm and a maximum of 20 mm, as well as a total areaweight of a minimum of 436 g/m²+/−10%.
 14. a method of producingheat-insulating-material mat (10) of claim 1 with a multi needle sewingmachine
 15. a method of claim 14, in which the seams (31,32,33) and/orthe rows of perforation holes (40) are executed, preferably during thesame production process, through needles of the multi needle sewingmachine, whereas in the case of production of the diffusion open variantof the mat (10) additional needles with no thread are inserted in thesewing machine, which can punch the extra holes (40) through the layers(1,2,3,4 . . . etc) in the same work process when making the seams(31,32,33)